Develop specific testing equipment, procedures, and analytical techniques which can be used to compare, rank, and eventually qualify candidate biomaterials with respect to their long-term mechanical durability in both cardiovascular prosthetic use and human-implantable circulatory assist devices. Specifically, the research will involve prediction and measurement of static and dynamic uniaxial creep, frequency and environmental effects on uniaxial dynamic tensile stress-strain behavior, prediction, and measurement of low-frequency biaxial tensile durability and reliability, and the effects of frequency and environment on biaxial tensile and flexural fatigue behavior.